Circuit closer



March 20, 1928.

P. R. NELSON CIRCUIT CLOSER Filed May '7, 1927 In ve/z ior Patented Mar. 20, 1928.

L Fl if PAUL R. NELSON, OF THE UNITED STATES ARMY, FORT TO'I'TEN', NEW YORK.

CIRCUIT CLOSER.

Application filed May 7, 1927. Serial No. 189,736.

(GRANTED UNDER THE PROVISIONS OF ACT OF MARCH 3, 1883, 22 STAT. L, 625.)

This invention described herein may be used by the Government, or any of its officers or employees'in prosecution of work for the Government, or by any other person in the United States, without the payment to me of any royalty thereon.

This'invention relates generically to electrical circuit closers and more particularly to the type utilized'in the operation of submarine mines.

I One object of this invention is to provide a circuit closer which not only establishes a perfect electrical path between its contacting elements but which retains such contact during a suflicient interval'to permit the proper functioning of mechanism within the circuit.

A further object'is to provide a circuit closer which is of simple and economical construction and efficient and positive in operation.

' With these and other objects in view this invention consists in certain novel details of construction, combination and arrangement of parts to be more particularly hereinafter set forth and claimed.

Briefly stated, this invention consists in a circuit-closer encased within a suitable housing which is attached to a submarine mine. The circuit closer comprises two electrodes, one of which is stationary and the other relatively movable in respect to the housing, and a spherical contact element which functions to either open or close the circuit by bridging a gap between the electrodes.

Referring more particularly to the accom- "panying drawings in which corresponding parts are indicated by similar reference characters:

Fig. 1 is a sectional elevation of the circuit closer showing the position of the con- "tact maker in open and closed position.

In describing the details of construction, which have been adapted for the purpose of illustration, the assembly of the entire mechanism will first be considered.

Referring to Fig. 1 the numeral (1) designates aball support, which forms one of the electrodes, (2) a ball which functions as a uniting element and (3) a'contact plate whichforms the opposite electrode. These three parts comprise the circuit makingand breaking elements of the device, which are constructed of suitable conducting materials.

The ball support (1) has an annular external surfacefll) with extending peripheries (5). Internally it is provided with a central circular opening (6) which spreads at its upper extremity to form the frusto-section of a cone (7) thereby providing a seat for the ball (2). The top and bottom surfaces (8) and (9) of the ball support (1) are preferably flattened, the bottom surface being provided with a central depending rim (10) which is internally threaded at (11) for the reception of. a conductor terminal (not shown). This element is preferably constructed of brass, the internal central opening (6) and the conical surface (7) being nickel plated.

Encasing the ball support (1) is an annular insulating shell (12), preferably made of hard moulded rubber and cast about the ball support (1); so that its interior projects betweenthe extending peripheries (5) on the surface of the ball support- The ex ternal surface of the shell (12) is annula-ted in sections (13), (14) and (15) having stepped diameters, the smallest annular section (15) encasing the depending rim (10) of the ball support (1), the largest section (13) being uppermost and threaded at (16), the upper extremity of its surface. The upper and lower surfaces (17) and (18) of the insulating shell (12) are flattened and parallel to one another and has a central conical opening (19) which aligns with that of the ball support. 1

A housing (20) is provided to enclose the mechanism and to also form a ground connection for the contact plate (3). This hous- I ing is composed of a cylindrical side wall (21) and top (22) and is preferably made of brass and nickel plated although any conducting material of sufficient strength will answer the purpose. The lower portion of the cylindrical wall. (21) is internall threaded at (23) to engage the threads (16) of the insulating shell (12),thus forming a waterproof enclosure for the contact mechanism;

: Mounted on the upper surface of the insulating shell (12) is a cylindrical spacing ring (24), having flat parallel upper and lower surfaces (25) and (26) and which fits snugly within the cylindrical side wall (21) of the housing (20).

Reclining on the upper surface (25) of the spacing ring (24) is the metallic contact plate (3), shown in Fig. 2, consisting of a disc. whichisofsmaller diameterthan the interior of the housing (20), thereby allowing a clearance which is suflicient to per mit the tilting of the same when it is pushed upward by the nickel plated steel-ball -(2) as will hereinafter be described; In the center of the' upper surface (27) of the pia'e' (3) is drilled a hole (28) which does .not. penetrate the entire thickness thereof and which is ofjust'suflicient diameter to engage the'central terminus (29) of a spiral spring (30). This spiral spring is interposed'betweenthetop22ofthe housing (20,) and the contact plate '(3) and is normally undera' cal surface (7) under the actionof' gravity.

The ball (2) closes the eleetric'al'circuit by wedgingjt'self'betweenthe conical surface (7 )"and lthecontact plate (3), thelatter. yielding slightlyto the wedging acti0n,,as, thefcompression of the spiral spring reacts against the tilting action thereof anjdretain the ball in contact. The closing of. the cir cuit completes the first event in'thecycle which is'ne'cessary to the automatic firing of thefinine. i

The mass. of the contact plate (3,), theresilienceof the spring (30) the mass of the ball (2)' and the coeificientof friction betweenthe surfaces all function unitedly to provide the yielding resistance toovercome theimpactof the contacting elements. This.

resistance iot only prevents damage to said elements-but also prevents the instantaneous rebound caused by the sudden contact thereof, which would be detrimental to the operation-of the (device, since it is necessary that.

the circuit remain closed for an appreciable duration of; time to allow the gproper' functioning of the detonating mechanism.

Thewiping contact of the steel ball (2).-

wedging. itself against the contact. plate (3), as its inertia carries it outward on the conical surface ,(7) ,produces a contact which is unfailingly self restoringiand non-jam Patent is:

Tlie',lower surface, (31) of contact plate (3) is normally. held throughout its circumel e st up e surface (2 a the IS'P fis i sIKZQJ b the s i pri ming; 'so that on return of the mine to a vertical position, the ball will be permitted to return by gravity to its seat.

While my invention is particularly adapted to be applied to electrical CiI'ClliltS-IEOIithB ignition of submarine mines, it will be readily-understood that it may be applied to 1other apparatus and usedfor other purposes than herein described, and that the arrange- ;ment-Wand structural details of my device may be considerably varied from what has been shownanddescribed without altering the mode of operation of invention or departing from its spirit and I desire that ch modi cati n sha1 .,b ncleds i ithin itsffscope.

Hausa -rd i bedry inventi n tha claim as newand wish to secure byl etters 1'. A device of' the' character,.described...v m mp ingi mbin t on w neduitab y n at et 's e s rs a l l sii i esed perpendicular position, one ,of the electrodes beingformed with a seat having. pwardly.j9

and outwardlyv flared walls, a ,contact plat'e situated above and: in vert c ll ,spacedre lation' to said seat, saidplate heing,,fInOVable,

I rectilinearly along and: angularly L about. its

vertical axis, f a spherical] memloen. of. cQn: .ir

tilted from the perpend-iculan ascending the inclined. Walls of itswseat engagement},

with the late to establish an electrical path; betweent e electrodes. 7

i A ss e Q- bf the racte des ribed fcomprising in co nbination a pair .of suit-. ably insulated ,electrodes. ,nornialljy. disposed in a perpendicular position, one of theielecw trodes being forme'cllwith a ,se athaving up;

wardly, and outwardly; fiit fed walls, ,a. 20, 111 tact \plate situated above.tandin vertically, spacedrelation w th .respectwto saidlseat,,a:

mounting for the plate permitting .m ye-i ment .thereof .rectilinearly along and. ,angu:

rl ab i k X n .a a stsai m un n includ ng a compression spr ng anchored at:

the center of the ,plate, a spherical .member of conducting material. positioned with f seat, said member when the electrodesare.

. one end and .CQImectedatits free extremity-to tilted from the perpendicular ascending ,the i inclined walls of its'seat into engagement with the plate where-fit: is frictionally ,ree v tained by the latter durin'g a predetermined portion of the period required for stherest'oration of electrodes to their normal posh,

tion.

comprising ,in combination a base of insu 3. A device of .ithe character described lating vmateriahia seat of v conducting, ma-v terial within thebase said seat having u base, said cap and.

e o st tu ng Pai i .wardly and outwardly flared'inclined walls, a metallic .cap mounted on said -.insul;at ing. I

[ducting material. positioned. within ,sa id., 2

seat, [said member when the. electrodes. are

10 establish an electrical path between said electrodes and a compression spring interposed between the plate and the top of said cap and exerting sufficient pressure upon the plate to retain the spherical member in contact with the plate during a predetermined portion of the period required for the restoration of the electrodes to their normal position.

PAUL R. NELSON. 

